Method of making foldable wooden lamellae for folding doors and the like



Nov. 4, 1969 s. VIOL ET AL METHOD OF MAKING FOLDABLE WOODEN LAMELLAE FORFOLDING DOORS AND THE LIKE 4 Sheets-Shet 1 Filed Aug- 2. 1967 INVENTORSGUNTER VIOL WERNER KOHFELD VIOL ET AL METHOD OF MAKING FOLDABLE WOODENLAMELLAE Nov. 4, 1969 FOR FOLDING DOORS AND THE LIKE 4 Sheets-Sheet 2Filed Aug. 2, 1967 O M A IVE-ZNTORS GUNTER vnon.

WERN ER KOHFELD Nov. 4, 1 969 s. VIOL ET AL METHOD OF MAKING FOLDABLEWOODEN LAMELLAE 1 FOR FOLDING DOORS AND Filed Aug. 2, 1967 THE LIKE r 4Sheets-Sheet 3 INVENTORS GUNTER VIOL v 7 WWW/5&4? MVA I WERNER KOHFELDVNov. 4, 1969 G. VIOL ET AL 3,476,630 METHOD OF MAKING FOLDABLE WOODENLAMELLAE FOR FOLDING DOORS AND THE LIKE Filed Aug. 2, 1967 4Sheets-Sheet 1 INVENTORS GUNTER VIOL WERNER KOHFELD United States PatentOfi ice 3,476,630 Patented Nov. 4, 1969 3,476,630 METHOD OF MAKINGFOLDABLE WOODEN LAMELLAE FOR FOLDING DOORS AND THE LIKE Gunter Viol, 276Bloherfelder Strasse, 29 Oldenburg, and Werner Kohfeld, 104 BreiteStrasse, Brake-Unterweser, Germany Filed Aug. -2, 1967, Ser. No. 657,970Claims priority, application Germany, Aug. 4, 1966, L 54,250; Jan 17,1967, L 55,509 Int. Cl. B32b 31/10 US. Cl. 156-268 6 Claims ABSTRACT OFTHE DISCLOSURE The disclosure relates to a method of making a coverforming wooden lamellae for accordion doors and the like in sectionscorresponding to the length and height of the cover desired, in which acover veneer of the desired length and height has its outer surfacetemporarily adhered to a plywood carrier of the same length and height,after which grooves that are too extend vertically of the cover veneerare formed in the cover veneer and the side of the panel carrier inspaced relation to define said cover veneer into alternating wide andnarrow strips. A similar panel from which the cover in question isfor-med and having the same height and length with such grooves alreadyformed in the front side of same has glued to its front face spacedtextile strips that respectively overlie the pairs of closely spacedgrooves that said grooves define, with further veneer strips beingsecured to such panel to fill in the space between the textile strips.The cover veneer is then glued to the cover forming panel across thesaid strips, with the grooves of each in alignment, and a blind veneerapplied to the back side of the panel in question, after which thecarrier panel is removed from the front side of the cover veneer toprovide a panel from which a subsequent cover forming panel can be made.The back side of the cover forming panel in question is then formed withwedge shaped notches respectively aligned with and opening to thegrooves formed on the front side of the panel to divide the panel inquestion into wide and narrow articulated sections. Covers so made arethen applied to the opposite sides of a lazy tong type support to forman accordion door.

The invention relates to a method for the production of preferablymultilayer foldable wooden lamellae, interconnected by articulated tapeswhereby said tapes are covered by a covering veneer or the like,particularly for producing double shell folding doors (literallyaccordion doors) and a folding door made in accordance with this method.

Folding doors comprise vertically arranged, stiff lamella partsinterconnected by hinges, hinged tapes or articulated tapes, so thatduring the opening and closing of the door the lamella parts can bemoved in an accordion-like manner.

The mass production of such wooden lamella connected with each other byarticulation is extremely difiicult because the double shell woodenfolding doors known from prior art have lamellae of varying width,depending on the width of the room. The width of the lamellae thereby isalways a fraction of the width of the room. Another disadvantage of thelamella made in line with the width of the room is. that the frontalsurfaces of the lamellae always diverge.

These disadvantages are avoided by the door according to th invention.According to the invention the lamellae are mass-produced at uniformwidth, whereby at different room widths the lamellae in the door areplaced at different angles to each other. Instead of the hitherto openanterior bisecting edges intermediate rods are glued in parallel to theoperating direction of the door, which are in the same plane as thelamella surfaces.

As a rule the hinges, hinge tapes, or articulated tapes are placed onthe inside of the wooden lamellae, resulting in the disadvantage thatwhen the door is folded the frontal sides of the wooden lamellae becomevisible; this looks bad and makes it necessary to cover these frontalsurfaces likewise with veneer.

In order to obtain a better optical overall impression, it is proposedto arrange the articulated tapes on the outside of the wooden lamellaeand to cover them with covering veneer. Thereby, the covering veneer isapplied in strips to the individual wooden lamellae, so that a fugueremains between the covering veneers of two adjacent wooden lamellaewhich is flush with the fugue located behind th articulated tape betwenboth wooden lamella, whereby the mobility of the articulated tape ismaintained as the door is moved.

It has been discovered that a sufficiently precise application of thecovering veneer strips to the lamellae is practically unfeasible in massproduction. It is impossible to glue the cut veneer to the plywood withthe precision of a fraction of an inch and to obtain that way arelatively wide and straight fugue. During the compression resultingfrom the gluing, the veneer may shift, making the desired preciseexecution of the fugues at the folding points, by which the opticaloverall appearance and the operation of the door are influenceddecisively, unattainable.

The aforementioned difficulties are to be obviated by the invention.

This problem has been solved by fastening a covering veneer on thesurface side removably to a carrier plate, for example by gluing it onvery lightly, by cutting into the cover veneer from the bottom atpre-determined intervals, first, longitudinally extending grooves, bycutting into the surface of a lamella panel second grooves extending inaccordance with the first grooves, by fastening to the surface of thelamella panel articulated tapes covering the second grooves, by placingthe carrier plate with the cover veneer upon the lamella panel so thatthe grooves match, and by gluing the cover veneer to the lamella panel,by cutting the lamella panel from the bottom side, preferably wedge-likeas far as the second grooves and by removing th carrier panel from thecovering veneer.

In the lamella panels the articulated tapes are applied only aftercutting the grooves so that they cannot be damaged by the cutting tools.The cover veneer also is held firmly, after the application of thegrooves, on the carrier plate until it is glued to the lamella panel.This fully maintains the straight and uniform course of the grooves andof the grain of the wood over the entire front surface of the doorwithout any shifting.

Another advantage of the method consists in that the panel first used ascarrier panel can be used in the further course of the production as apre-grooved lamella panel. This renders the method even more economical.

In order to obtain a smooth front surface as support surface for thecover veneer, it is possible to apply compensating veneer strips betweenthe articulated strips or a milling may be applied to the plywood at adepth somewhat less than the thickness of the articulated tapes. Thefastening of the articulated tapes or strips, of the compensating veneerstrips and the cover veneer on the lamella panels can be accomplished bygluing.

According to a further development of the invention a folding door withthe lamella element made according to the invention has been created,characterized in that intermittent bars are arranged between the lamellaelements whose anterior surfaces are in one plane with the anterioredges of the basic bodies of the lamellae, in other words they areneither recessed nor projecting, and that the lamella elements and theintermediate bars are connected by articulated strips veneered below thecover veneer and forming one unit with the material of the basic lamellabodies and of the covering veneers.

In this embodiment the frontal sides of the lamella elements, located onthe outside when the folding door is folded, are corners withoutseparately projecting or recessed edges, because the frontal surfaces ofthe lamella elements are covered up by the intermediate bars. Thelamella elements and the intermediate bars are covered by woodenveneers. Due to the fact that the front surfaces are close together andcontinuous in one plane that is the front surfaces of the basic lamellabodies and of the intermediate rods or bars the folding door then showsa decorative pat-tern of the wood graining, as it is neitherdiscontinuous nor shifted. Only with this design is it possible to showa continuous wood pattern with the natural veneer design, the like ofwhich no wooden folding door could show anywhere in the world. For theproduction it is favorable that the after-veneering of the longitudinalfront edges of the lamella elements is eliminated. The articulatedstrips may be colored according to the color of the lamella elements. Itis possible to use simple fabric or plastic tapes or such tapesreinforced by inserts as material for the articulated strips.

According to a further development of the invention the design may besuch that the front ends located on the inside in folded position ofsaid lamella elements are connected to carrier rods or bars fastened atthe shearing skeleton, whereby two adjacent front ends each are insertedand fastened in a vertical slot in the carrier bar, so that with thedoor fully extended the front surfaces of the lamella elements of theintermediate bars form a smooth surface. This embodiment offers theadvantage that with the telescoped or folded lamella position the outersurfaces of the intermediate rod adhere flatly to each other, so thateven the telescoped or folded door package shows a smooth decorativewood pattern in one plane. This embodiment furthermore offers theadvantage that even in the folded position of the door package hollowspaces remain between the individual lamella elements into whichsoundproofing inserts may be installed, for example,

Embodiments of the invention which show additional features of saidinvention are shown in the drawing.

FIGURE 1 shows in a sectional view a cover veneer fastened to a carrierplate 2 for the front sides of wooden lamellae 1 intended for a foldingdoor,

FIGURE 2 shows in a sectional view a carrier plate 2 with cover veneer 1according to FIGURE 1, with the grooves 2 cut in,

FIGURE 3 shows in a sectional view lamella panel 4 with cut-in grooves 5and articulated tapes 6 glued on and overlapping the grooves 5, alongwith a compensating veneer 7,

FIGURE 4 shows in a sectional view the assembly of the cover veneer 1,the carrier plate 2 with the lamella panel 4, and

FIGURE 5 shows the lifting of the carrier panel 2 from the cover veneer1 now solidly glued to the cover veneer 1 and the wedge-like cutting out9 of the lamella panel 4 from the rear,

FIGURE 6 shows a perspective view of a door design where the woodenlamellae produced according to the method are used,

FIGURE 7 shows a longitudinal section thru the door according to FIGURE6,

FIGURE 8 shows an enlarged partial presentation from FIGURE 7 and FIGURE9 shows a lateral view of the presentation according to FIGURE 8.

The various steps of the method are shown consecu- 4 tively in FIGURES 1to 5. All lamellae of a folding door or of a major folding door section,wooden lamellae in the embodiment, are worked out of a wide plywoodpanel only at the end of the production, said plywood plate beingdesignated as lamella panel 4.

The cover veneer 1 with the proper dimensions to be applied to theanterior surface of the lamella panel is first glued removably with itslater surface to the lower side of a stable carrier plate 2 (FIGURE 1).The grooves 3 later extending vertically are cut into the cover veneer 1so fastened and into the carrier panel 2 from the bottom, whereby thecover veneer is separated into cover veneer strips which first remain atthe carrier panel 2.

Grooves 5 are placed into the front side of the lamella panel 4. Thegrooves 5 are placed at the'same intervals from each other as thegrooves 3 of the carrier plate and also agree as to width with thegrooves 3. The front surface of the lamella panel is then so glued withthe articulated strips 6, textile strips for example, that the grooves 5of the lamella panel are covered on both sides with sufficientoverlapping. In order to obtain a smooth front surface compensatingveneer strips 7 are glued between the articulated tapes on the lamellapanel.

To a lamella panel so prepared the carrier plate 2 with the cover veneer1 is now glued, whereby the grooves 3 and 5 are placed matchingly oneach other and the cover veneer is glued firmly to the front surfaces ofthe articulated tapes 6 and the compensating veneer strips 7 (FIG. 4).At the same time the rear side of the lamella panel is glued to theblind veneer 8 during this operation.

Now that the cover veneer 1 is firmly glued to the lamella plate, thecarrier plate 2 is removed from the covering veneer 1 (FIG. 5). Thecarrier panel 2 thereby released becomes during the further course ofoperation the lamella panel. The lamella panel is cut wedge-like (9)from the bottom precisely below the grooves 3, so far that each wedgecut 9 reaches the superposed groove 3 from the bottom. The wedge-likedesign of the notches 9 establishes the mutual mobility of the lamellastrips so that after the assembly into the folding door they can bedisplaced bellows-like and can pivot thereby.

FIGURES 6 to 9 show a double shell folding door with a shearing skeleton11 located therein and placed in a vertical plane, said skeleton beingcovered on both sides with one outer shell each.

Each outer shell is connected via vertically extending carrier bars 12made of wood with the shearing skeleton. Two basic wooden lamella bodies4 are placed between two carrier bars each. Between the longitudinalfront surfaces located on the outside in closing position of the basiclamella bodies one intermediate Wooden bar 13 is arranged extendingparallel to the anterior edges of the lamellae. Two basic lamella bodies4 form one lamella element with the intermediate bar. Near their outerand inner longitudinal edges the lamella bodies are coated on theirfront side with flexible articulated tapes 6. On the outside thearticulated tapes are guided over the intermediate bars 13 from onebasic body to another one and glued on. In the inner areas thearticulated tapes connect the basic bodies to the carrier bars 12. Theyhave on the outside surfaces 14 slanting toward each other. The frontedge formed by the slanted surfaces is slit open. The laterallyprojecting articulated tapes 6 of the adjacent lamella elements areplaced into said slot 15 and connected to the carrier rod by gluing,pasting or nailing. 10 identifies a wire pin.

A compensating veneer 7 is pasted between the articulated tapes on thefront surface of each basic body and the smooth front surfaces of thebasic bodies so formed and the intermediate bars covered with thearticulated tapes are covered by covering veneers. The adjacentlongitudinal surfaces of the basic bodies and of the intermediate rods13 are undercut. The inner surfaces of the basic bodies and theintermediate bars are coated with veneers likewise.

As the folding door is folded together smooth corners form on the outerends of the lamella elements, whose outer edges are formed byarticulated tapes, resulting in a near appearance.

We claim:

1. A method for the manufacture of preferably multilayer foldable woodenlamellae, interconnected by articulated tapes, said articulated tapesbeing covered by a covering veneer or the like, particularly for theproduction of double shell folding doors, characterized by the fact thata covering veneer (1) is fastened on the surface side to a carrier panel(2) removably, that first longitudinally extending grooves (3) are cutfrom the bottom into the covering veneer (1) and the carrier panel (2)at predetermined intervals, that second grooves (2) extending inaccordance with the first grooves are cut into the surface of a lamellapanel (4), that articulated tapes (6) covering the second grooves arefastened to the surface of the lamella panel, that the carrier plate (2)is placed with the covering veneer (1) on the lamella panel (4) so thatthe grooves match and the covering veneer (1) is connected to thelamella panel, that the lamella panel is cut, preferably wedge-like fromthe bottom side in to the second grooves (5) and that the carrier plate(2) is removed from the covering veneer.

2. A method according to claim 1, whereby the carrier panel (2) is usedin the subsequent operation as lamella panel (4).

3. A method according to claim 1 whereby the removable fastening of thecover panel veneer (1) to the carrier panel (2) is accomplished byslight gluing or pastmg.

4. A method according to claim 1, whereby compensating strips (7) arefastened on the lamella panel (4) between the articulated strips (6 5. Amethod according to claim 3, whereby the articulated tapes (6), thecompensating strips (7) and the cover veneer (1) are fastened to thelamella panel (4) by gluing.

6. A method according to one of the preceding claims, whereby thelamella panel (4) is made from plywood covered on the back side by ablind veneer (8).

References Cited UNITED STATES PATENTS 3,131,753 5/1964 Dixon a- 1601 83FOREIGN PATENTS 1,107,921 5/ 1961 Germany.

1,121,305 1/1962 Germany.

DOUGLAS J. DRUMMOND, Primary Examiner US. Cl. X.R.

